The present invention relates generally to the art of mixing food products. More particularly, the present invention relates to the mixing of ice cream or ice milk with flavoring components in a machine having a vertically fixed, motor-driven, mixing auger and a vertically reciprocating mixing cone. The present invention seeks to provide an improved means for vertically driving the cone to engage the auger.
It has long been desired to effectively mix ice cream and flavors in a palatable, easily served condition. In this respect a hard flavoring substance is frequently mixed in with softer ice cream, alternatively a soft flavoring substance may be mixed in with the ice cream. But, consumer desires are not limmited to simply mixing ice cream and the various flavoring products. From an economical point of view it is desirable to mix ice milk to produce various flavors. Likewise, other frozen desserts could be mixed in a machine utilizing the present invention. For convenience sake, this wide range of possible mixing substances will be referred to throughout the present application as ice cream, although it is not intended that the scope of the present invention by limited to uses involving ice cream solely; the spirit of the invention should be construed to include machines used to mix ice milk or other frozen desserts also.
The technology for effectively accomplishing the mixing of such products as ice cream or ice milk with flavoring products such as chocolate cookies has long been known. The most successful of the known devices for accomplishing the mixing, C. Reed, U.S. Pat. No. 2,626,132, uses an auger shaped mixing device and a cone shaped mixing container. Using this combination, it is possible to mix the ice cream and the flavoring substance into a softer, flavored product which can be extruded from the bottom of the cone into a dish or an ice cream cone. The present invention is directed towards a device or mechanism for bringing the mixing container, preferably an extruding cone, into engagement with the mixing auger.
The prior art has provided a number of methods for accomplishing this result. The most common of these devices, e.g. Ehrenfeld, U.S. Pat. No. 1,982,339; Stroud, U.S. Pat. No. 1,993,024; and, Carnahan, U.S. Pat. No. 2,110,498 utilize a dually groved shaft which is spun by the motor. The mixing container then rides up and down this shaft due to the spiral groving in the shaft itself. This is an automatic arrangement typically activated by a switch sensitive to the mixing container being vertically aligned with the mixing blades.
Another method which has been used to bring the mixing blades into contact with the mixing container is described in U.S. Pat. No. 3,352,543, Niederman et al., and involves the interconnection of a worm gear with a rack gear, one being fixed to the system housing and the other being fixed to the rotating shaft for the mixing blades. In this type of configuration the mixing blades may be driven vertically as the shaft rotates in a normal mixing operation. This is similar to the above described scheme in that the vertical reciprocation of the mixing container or blades is accomplished automatically when the mixing blades are rotated by the system motor.
However, it is not always desired that the system operate automatically. In fact, there are some applications of these mixing machines, such as home use, which seem to dictate manual operation.
The prior art also contains a teaching of the use of a manually operable lever for raising the mixing container into engagement with the mixing element. The most comprehensive teaching of this scheme is found in C. A. Reed, U.S. Pat. No. 3,061,279. This patent describes a method and mechanism for raising the mixing container by use of various cable and pulley connections. Through a chain and sprocket interconnection, the movement of the lever causes a cable to wind around a decreasing radius drum thereby raising the mixing container. The reverse causes the container to be lowered. In this situation, the most power and the least vertical speed is found at the end of the stroke when the auger is deeply engaged in the food product.
An earlier patent, C. A. Reed, U.S. Pat. No. 2,626,133, likewise teaches the use of a manually operable lever arm to cause the mixing container to engage the mixing auger. This patent uses a simple lever operation which may be fully depressed without immediately forcing the container to the top of the its vertical stroke; a spring biasing arrangement is set when the lever is pulled and the force of the spring replaces that of the operator to finish the vertical movement of the container.
However, much of the prior art has been directed primarily towards commercial applications of such devices. It is now desirable to produce a device which will allow the mixing of ice cream and flavors such as bananas, peanut brittle, or blue berries in the home. In this respect, the prior art is not acceptable and its teachings are deficient; the relative size and strength of force necessary to operate any of the prior art devices makes them impractical as a household product. For example, the lever action described above requires an undue amount of force to be applied to the lever to actuate the vertical movement of the mixing container. While this is acceptable in a commercial setting, it is impractical for operation on a kitchen counter in the home where the typical user is a housewife or child. Also, the devices currently available are quite heavy, some in the neighborhood of 250 lbs. Such a large weight keeps these machines from being acceptable in the home where counter-top mobility is desired and a fixed, permanent location for the machine is unlikely.
In the home it is desired to have a mixing device which is relatively easy to use and of predominantly simple construction. Also, such a machine should be light weight, durable, and easily cleaned. It is also desirable that the product made for home use provide a sure feel to the user, require only a relatively light force to operate, and yet provide a steady flow of extruded product.
Therefore, it is the primary object of this invention to provide a frozen dessert mixer for use in the home which is capable of mixing ice cream and flavoring products. It will be appreciated then that a further object of the invention is to provide for the relatively easy vertical drive of a mixing container into engagement with a mixing element.
It is also an object of the present invention that the operation of the device not require undue stength or exertion by the operator.
It is a further object of the present invention to provide for the extrusion of a steady stream of mixed product.
It is still a further object of the present invention to provide for steady, true vertical movement of the mixing container without substantial binding on internal guides.